Kalwang is a municipality in the district of Leoben, in the Austrian state of Styria. It lies in the federal province of Styria in southeastern Austria, within the administrative district whose seat is the city of Leoben.
As a municipality, Kalwang is one of the local administrative units that make up the Leoben district, a district in the state of Styria. The municipality is situated in the mountainous Alpine terrain characteristic of this part of Austria.